“But sanctify the Lord God in your hearts: and be ready always to give an answer to every man that asketh you a reason of the hope that is in you with meekness and fear..." 1 Peter 3:15

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Monday, December 08, 2014

The Impropriety of Trying to "Prove" The Absolute Truth Value of a Transcendental Inductively

For x (some aspect of human experience) to be the case, y must also be the case since y is the precondition of x. Since x is the case, y is the case.M.B.
Applying the above transcendental formulation in traditional form we end up with:

Prove A:The Christian God exists.
Step 1 ~A: (Assume the opposite of what we are trying to prove): The Christian God does not exist.
Step 2 (~A--> B): If God does not exist, then there is no intelligible experience since God is the precondition of intelligibility
Step 3 (~B): There is intelligible experience (Contradiction!)
Step 4 (~ ~A): It is not the case that God does not exist (Modus Tollens on 2 and 3)
Step 5 (A): --> God does exist (Law of negation.)

Many Christians hold to the above argument, which is transcendental in nature. A common debate among certain apologists will be over whether step 2 can be shown to be philosophically justified. Immediately below is what I believe to be a feeble justification for step 2 of the above proof but I have seen it enough that I believe it is worth interacting with.

Subsidiary "argument" that is intended to justify step-2 of TAG:

Premise 1: Within the worldview of Christianity intelligibility can be justified.
Premise 2: All worldviews that we have been confronted with cannot justify intelligibility.
Conclusion: Since we cannot deny intelligibility, and since only the Christian worldview so far can justify it, then the Christian worldview is true.

Some believe that step-2 of TAG can be inductively proved because every worldview that a particular apologist had encountered has been refuted. It is argued by such apologists that the “rational inference” that God exists is based upon a statistical-confidence one might have from refuting many opposing worldviews. One of the problems I have with this justification is how can an inductive argument justify the God of Christianity when it cannot justify the heart of Christianity, the Resurrection of Christ? In other words, an inductive justification for step-2 presupposes uniformity in nature, yet the existence of the Christian God requires discontinuity, the Resurrection! How does one plan on justifying discontinuity on the basis of induction, apart from presupposing the self-attesting word of God? Moreover, the conclusion of the subsidiary argument that is intended to justify step 2 of the transcendental argument, which is “the Christian worldview is true,” exceeds the scope of the premises. Induction is a posteriori in nature and can only yield as its maximal conclusion something that is probably true. To conclude that something is true by inductive inference is to employ the fallacy of asserting the consequent. If step 2 is probably true, then it might also be false; yet Christians have a more sure word of knowledge. Moreover, that the Christian worldview is "more reasonable" than the non-Christian worldview remains unjustified because the question of whether one is even philosophically justified in his use of induction, so that rational inference may be drawn, has not been established. There are no freebies in Philosophy.

In order to rationally infer that God’s existence is "most probable,” one must first presuppose that which the conclusion of the subsidiary argument does not afford – God’s actual, ontological existence(!), which is the necessary precondition for inductive inference. This problem is insurmountable. In arguing for the high probability of God’s existence, the apologist, like the unbeliever who argues against God’s existence, presupposes tools of argumentation that presuppose God’s actual existence. The subsidiary argument, which concludes that God might not exist, begins by presupposing the actual intelligibility of both deduction (TAG) and induction (the justification for step 2), which presuppose God's actual existence! Accordingly, one’s presupposition of God’s actual existence ends up contradicting his conclusion that God’s existence is only probable. Accordingly, one would have to revise his presupposition-hypothesis to “God might not exist.” In doing so, one will not be able to justify actual induction or deduction. Actual rationality presupposes neither a probable God or a conceptual scheme. In order to infer that God’s existence is philosophically uncertain, one must first borrow from a worldview that comports with philosophical certainty so that there can be philosophical uncertainty. That worldview is the Christian worldview.

In summary, the Christian need not evaluate an infinite number of worldviews in order to know (and justify) that there are only two worldviews. In the like manner, the Christian need not witness an infinite amount of deaths to know that all men are mortal. We have an appeal for such premises, the truth of God’s word, which tells us that there are only two worldviews; one is that revelation is the necessary precondition for the justification of intelligible experience and the other is a denial of the Christian worldview. Moreover, induction requires as its necessary precondition something more than a conceptual scheme for God’s existence.

TAG is sound in that the form is valid and the premises are true. We must keep in mind that the truth of any valid conclusion is not predicated upon the consensus of the truth of the premises. Accordingly, since unbelievers will not accept the truth claims of the Bible and, therefore, step 2 of the proof, the only thing the Christian can do is refute the hypothetical competitors. In doing so we might gain more psychological confidence that God exists. Notwithstanding, a demonstration of the soundness of an argument does not make an argument sound. The apologist merely demonstrates the veracity of TAG to a watching world when he exposes the various forms of the one unbelieving worldview for its arbitrariness and inconsistencies.

There is no limit to the number of sound deductive arguments for the Christian worldview. Most of which are not very useful or interesting, such as: God exits or nothing exists; not nothing exists; therefore, God exists. As Dr. Bahnsen noted, proof of the Christian worldview is child's play. The beauty of TAG as a special kind of deductive argument is not in the reductio but in the transcendental challenge, which shows that to argue against Christianity one must first presuppose only that which Christianity affords.

57 comments:

This brief exchange was made under another blog-entry but it refers to this entry:

Hello Ron,

I just recently found your blog and I really appreciate it. I am looking forward to reading your TAG argument and defense of Theonomics.

A Question/Comment:

In reading some of your past entries I came across "The Impropriety of Trying to Prove..."

I'm not sure I understand completely your conclusion. It seems that you are saying that TAG commits the argumentum ad ignorantiam fallacy?

From my understanding, this fallacy does not operate under the same conditions that non-theist systems operate under.

The Christian does not presuppose the ultimacy of Chance and therefore the argumentum ad ignorantiam (AI) is very limited in its scope. Presupposing the Christian worldview relieves one from the burden of always committing an AI on any conclusion (which all non-believing worldviews create, by Christian presupposition of course). One can thus only charge the Christian of AI in his premise-conclusion by presupposing its falsity. So naturally we come to the conclusion that Van Til et al had been asserting all along; that one must presuppose the Christian worldview. In this, there is no inductive problem from said premise 2 of your post unless one has already presupposed the falsity of the entire argument; however in doing so one cannot prove the falsity of anything because they commit the AI.

However, I may have misunderstood your post.

Mr. Anonymous.

8:16 PM

Ronald W. Di Giacomo said...

I'm glad you enjoy the blog. Thank you very much.

The argument that something must be true simply because it hasn't been proved to be false, or vice versa, commits the fallacy of ignorance. TAG does not commit this fallacy. I didn't mean to communicate that TAG is fallacious. TAG is sound in and of itself. My contention was with the impropriety of trying to prove step-2 by inductive inference. First off, induction cannot prove an abolute truth. Secondly, the conclusion of the subsidiary, inductive argument for step-2 is self-refuting for it presupposes what it denies in its conclusion. In other words, the inductive "proof" aimed at establishing step 2 of the TAG argument I put forth presupposes God's actual existence whereas the conclusion of the inductive argument is that God probably exists. The probability of God existing cannot justify induction and, therefore, the subsidiary argument, nor can it justify deduction and, therefore, TAG. The point of that post was not so much to vindicate TAG but to show the wrongheadedness of trying to prove step two by inductive inference.

By refuting competitive worldviews one by one, the veracity of the Christian worldview is demonstrated, not proved. The Christian worldview is proved true by TAG alone.

Did you have me in mind when you wrote this? I plan on starting a series on VanTillian Presuppositionalism soon. You are more than welcome to critique it. It is still my position that the argument proposed by Bahnsen is not certain, but rather has an inductive element. You illustrated this element when you spoke of the justification of step 2.

Yes, I most certainly had you in mind. If one tries to justify step-2 inductively, then yes the argument fails to be what Bahnsen might have hoped for. However, we need not justify the the 2nd premise inductively. Accordingly, what Bahnsen hoped for is in reach, which he also understood.

As I wrote:

"The Christian need not evaluate an infinite number of worldviews in order to know that there are only two worldviews, anymore than he needs to witness an infinite amount of deaths to know that all men are mortal. We have an appeal for such a premise, the truth of God’s word. Moreover, induction requires as a necessary precondition something more than a conceptual scheme for God’s existence.

The proof for God's existence is sound in that the form is valid and the premises are true. We must keep in mind that the truth [Or Soundness] of any deductive conclusion is not predicated upon anyone's agreement of the truth of the premises. Accordingly, since unbelievers will not accept the truth claims of the Bible and, therefore, step 2 of the proof, the only thing the Christian can do is refute the hypothetical competitors. In doing so we might gain more psychological confidence that God exists. Notwithstanding, a demonstration of the soundess of an argument does not make an argument sound. The apologist merely demonstrates the veracity of TAG to a watching world when he exposes the various forms of the one unbelieving worldview for its arbitrariness and inconsistencies."

Brian,

Whether you believe that Bahnsen had what you called a "certain" argument, my argument is indeed sound.

My problem with your apologetic is that you employ induction in order to to try to prove that God probably exists, yet induction and probability presupposes God's actual existence - something that cannot be proved by induction! Accordingly, your justification for induction presupposes that which your argument denies - God's actual (not probable) existence! I have always felt your problem stems from a want of appreciation for what proof entails, which might come from a confusion over the difference between proof and persuasion.

I will respond once and let you have the last comment. (By the way, you are doing a great job on your blog.)

(1) You said, “We have an appeal for such a premise, the truth of God’s word.” This is where the Van Tillian begs the question. The proof for God’s existence and the truth of the Scriptures as being God’s word are one and the same.

(2) You said, “The proof for God's existence is sound in that the form is valid and the premises are true.” I find the proof sound, but any justification for step 2 is not based in philosophical certainty. If there is a philosophically certain justification for step 2, then someone should present it. I think it speaks volumes that no Van Tillain has ever presented such a justification. Again, an appeal to Scripture at this point begs the question.

(3) You said, “My problem with your apologetic is that you employ induction in order to to try to prove that God probably exists, yet induction and probability presupposes God's actual existence - something that cannot be proved by induction!” It is my claim that the situation between you and me is this:

As to my presupposing God’s actual existence when I expect the tooth paste to come out when I squeeze the bottle, I do not argue with this. However, the reason I don’t argue with this is not because I am philosophically certain in my belief, but rather because I am rationally justified in my belief.

(4) You said, “Accordingly, your justification for induction presupposes that which your argument denies - God's actual (not probable) existence!” My justification for induction is that I am rationally justified in believing in God’s existence. The difference between you and me is that I do not believe I have philosophical certainty about anything, whereas you think you do. I have yet to see a philosophically certain proof for God’s existence. Again, it is funny how Van Tillians are rather short on this side of the argument. They do a good job presenting arguments against other worldviews, but ultimately fail to provide what they say they have.

Wow, I don't know how long ago this exchange took place, but I am always impressed, Ron. Very encouraging. Perhaps Brian is truly autonomous in his reasoning (explicitly, at least!), but I admit that the concept of all ultimate truth claims being circular by nature is a tough pill to swallow. Nevertheless, I think you demonstrated that that isn't his problem, he did admit that TAG was sound and then in the next breath demanded a "philosophically certain" proof. I really have no idea what that is if not sound.

I'm curious, you wrote that people are certain, but arguments are not. Is that a typo? TAG is logically certain. Christians are psychologically certain (or should be, anyway) due to the inner working of the Holy Spirit. This would seem to be the difference between proof and persuasion.

Interestingly, John Frame says in his _The Doctrine of the Knowledge of God_ that logical and psychological (Cartesian) certainty ultimately reduce to the same thing, which would perhaps nullify your dichotomy between proof and persuasion. Thoughts?

You wrote: "I'm curious, you wrote that people are certain, but arguments are not. Is that a typo? TAG is logically certain.

You agree that TAG is sound and that people can be certain of truth. Now what do you mean that TAG is "certain" (or certainly true)? If all you mean by that is that TAG is sound and we can be certain of TAG, then why not leave it there? What more are you saying by "TAG is certain?"

At the end of the day Brian's philosophy reduces to skepticism. This is because he thinks that logic and induction are more ultimate than their justification, which is special revelation. He proceeds to argue against the soundness of TAG as he assumes the soundness of induction and deduction, which obviously presupposes the ontological existence of God. And we can only justify the actual existence of God by appealing to Scripture, which of course Brian calls begging the question - and that is where he confuses proof with persuasion.

"Interestingly, John Frame says in his _The Doctrine of the Knowledge of God_ that logical and psychological (Cartesian) certainty ultimately reduce to the same thing, which would perhaps nullify your dichotomy between proof and persuasion. Thoughts?

Even if I were to grant that the feeling one gets from inductive inference is on par with the certainty one can have by way of sound deduction, I don't see how such a psychological phenomenon applies to the disucussion of proof vss. persuasion. For instance, as long as an unbeliever is an unbeliever, he will never be persuaded by a sound proof nor an inductive argument that is pretty strong.

I agree with Bahnsen and Frame in that Cartesian certainty and logical certainty are two distinct types of certainty. (Although Frame later argues that they reduce to the same thing.) Logical certainty is the property of a proposition in that it cannot fail to be true. Cartesian certainty is the absence of all doubt, and thus it is the property of an individual.

When you say, "TAG is sound and we can be certain of God," you are really expressing both forms of certainty. "TAG is sound" refers to its logical certainty. "We can be certain of God" refers to Cartesian certainty.

I see this as relating to proof and persuasion because a proof is logically certain by definition, whereas persuasion involves Cartesian certainty by necessity. (At least, in this case, for Christianity.)

My inquiry, then, is whether Frame is destroying the dichotomy between proof and persuasion because he denies the dichotomy between logical and Cartesian certainty.

If Frame is correct, then so was Descartes in that proof demands persuasion. This brings in the question, "Why isn't the unbeliever persuaded, then, if the proof is certain?" And the answer, of course, is that the Holy Spirit has not enlightened them. Thus certainty comes only through the Holy Spirit.

“I agree with Bahnsen and Frame in that Cartesian certainty and logical certainty are two distinct types of certainty. (Although Frame later argues that they reduce to the same thing.)”

Raz,

Can something be logically certain and unsound? If yes, then what you’re speaking about are valid arguments that can be unsound due to false premises. If no, then logically certainty would reduce to sound deductive arguments, in which case it is simply equivocal to speak in terms of the certainty of an argument.

“Cartesian certainty is the absence of all doubt, and thus it is the property of an individual.”

If that is true, then one can be certain and wrong, or certain an unjustified, etc.

“I see this as relating to proof and persuasion because a proof is logically certain by definition…”

NO. A proof can be unsound yet valid or simply invalid and, therefore, unsound. To speak in terms of logical certainty gets us nowhere as my first comment above addresses.

Can something be logically certain and unsound? If yes, then what you’re speaking about are valid arguments that can be unsound due to false premises. If no, then logically certainty would reduce to sound deductive arguments, in which case it is simply equivocal to speak in terms of the certainty of an argument.

No, something cannot be logically certain and unsound. I think that's true by definition, no? (see my later comment) Anyway, what is equivocal about that? What other option is there?

If that is true, then one can be certain and wrong, or certain an unjustified, etc.

That's why I don't like talking about certainty exclusively in Cartesian terms. (I argued this in my most recent blog post, if you are interested.) Anyway, in a previous email you defined certainty as Cartesian certainty, so I'm confused as to what your problem is now.

NO. A proof can be unsound yet valid or simply invalid and, therefore, unsound. To speak in terms of logical certainty gets us nowhere as my first comment above addresses.

Well, I should have tacked "sound" in front of "proof". Sorry about that.

"No, something cannot be logically certain and unsound. I think that's true by definition, no? (see my later comment) Anyway, what is equivocal about that? What other option is there?"

Raz,

Then logically certain means sound. So why not leave the realm of certainty to persons and not arguments?

I would say it's equivocal because one can feel certain without having a technically *sound* basis for that certainty - for instance in those cases where the certainty comes from inductive inference or false premises by which one deduces an unsound yet *valid* conclusion. Now of course you will say that in such cases the person may feel certain without truly being certain. However, such would be equivocal since "certainty" of belief is not usually limited to deductive arguments that are sound or revelation that is true. Consequently, since one can be certain without deduction or revelation, then one can be certain while being wrong. His certainty would be based upon an unsound argument or false revelation. Here's the punch line: If one can be certain yet wrong, then why say that "certain" arguments MUST be right? The equivocation comes by way of talking about certainty with respect to arguments in a way that is not analogous to the certainty of what one believes. With respect to beliefs, one can be certain yet wrong. So why insist that "certain" arguments are always sound? Why can't they be valid yet not sound? With all that said, I prefer to talk of sound and unsound arguments and leave certainty to persons.

Ron: The problem with Brian's position is clear to me. He doesn't accept that a premise can be justified in a sound argument by appealing to God's word. What Brian is left with is establishing something other than God's word as his final / ultimate authority. The problem Brian encounters is two-fold (IMHO). 1) Brian does not accept valid arguments that use true premises if those premises are justified by God's word. Brian confuses proof with persuasion which you know all to well. 2) Brian cannot justify logic as an ethical system that we are called to live in accordance with, let alone a universal system that is invarient etc., unless he presupposes God's word - which he will not do since he thinks that to do so is to beg the question. Brian presupposes logic without a justification, and if he were to appeal to the Scriptures for his justification, then he'd have to be willing to accept an appeal to Scripture to justify true premises.

The only question I have is whether Brian thinks he believes God's word on it's own testimony, as the WCF teaches in Chapter 1, or does Brian think he believes Scripture because of an argument that he cannot justify...

“We have an appeal for such a premise, the truth of God’s word.” This is where the Van Tillian begs the question. The proof for God’s existence and the truth of the Scriptures as being God’s word are one and the same."

Brian, actually the "proof" for God's existence is not the same thing as the premise that God has revealed himself, or that the Scriptures are God's word. You're confusing proof with premise.

As for begging the question, you aren’t appreciating the necessity of circular reasoning when dealing with ultimate truth claims.

("2) You said, “The proof for God's existence is sound in that the form is valid and the premises are true.” I find the proof sound..."

Ha, well if you find the proof sound, then what more can I do? That is what I set out to do, is it not? Put forth a sound proof?

"...but any justification for step 2 is not based in philosophical certainty."

Brian, we've discussed this for years and have gotten nowhere. The justification for step two is based upon God's word. Your problem is that God's word, for you, is not authoritative. You don't submit to it as God's self-attesting Word. Yet you will submit to inductive inference, which can only be justified if God's word is first true! Consequently, you allow for reason in an arbitrary sense because you do not affirm the only justification for reason.

"If there is a philosophically certain justification for step 2, then someone should present it."

Brian, I have presented many sound deductive arguments to justify step-2, yet you say they beg the question even though they are sound. If an argument is SOUND, then obviously the truth values are justified, otherwise how can one say the argument is sound?! You now suggest that sound arguments are not necessarily philosophically certain? What in the world is philosophical certainty? People are certain, not arguments.

"I think it speaks volumes that no Van Tillain has ever presented such a justification."

My friend, I think it speaks volumes that you don't know what it means for an argument to be sound.

Brian, the possible existence of a non-ontological god is not a justification for induction. In other words, conceptual necessity does not imply ontological necessity. Accordingly, you have no claim on induction without justifying step-2 by appealing to Scripture. Such an appeal, as you are willing to admit, does not make the argument unsound. What you don't get is that you appeal to senses, truth and uniformity, which can only be justified if Scripture is God's revelation. To justify induction is to justify Scripture as a true premise! You have yet, in all this time, grasped Van Til, Bahnsen or Frame.

"the reason I don’t argue with this is not because I am philosophically certain in my belief, but rather because I am rationally justified in my belief."

Brian, implicit in your argument is that rationality does not presuppose God, which is arbitrary and inconsistent. What is rationality after all and how do you know your answer is true?

"(4)My justification for induction is that I am rationally justified in believing in God’s existence."

Plantinga? Yes Brian, you are justified but you are not prepared to give a sound justification because you deny the need to base all argumentation on the authority of God's word.

The difference between you and me is that I do not believe I have philosophical certainty about anything, whereas you think you do.

That's right, Brian, you are a philosophical skeptic by creed. Those words are sincere and true and not to be inflammatory.

I have yet to see a philosophically certain proof for God’s existence.

I gave you a sound proof by your own admission. Now you want something called "a philosophical certain proof." What's that, Brian, an argument that is not sound yet appeals to autonomous reason?

"Again, it is funny how Van Tillians are rather short on this side of the argument. They do a good job presenting arguments against other worldviews, but ultimately fail to provide what they say they have."

Brian, I have proven God’s existence with a valid form and true premises, making the argument “sound.” You agree with the premises and the form yet you want to say I am begging the question. Our difference is that you feel you must justify step-2 by induction. I too am willing to demonstrate inductively that all variations of the single, unbelieving worldview do not supply the necessary preconditions of intelligible experience. However, that does not make the premise true nor can it be the bases by which one knows the premise (as true). It merely confirms what the Bible says.

"To some it might seem that step 3 is also verified apart from scripture. Have you run into that before?"

Hi Keith,

People know it apart from Scripture but it cannot be justified apart from Scripture.

"Also, John Robbins says that TAG would only be valid if step 2 reads: if and only if God does not exist will there be no intelligible experience. Thoughts?"

I'm more interested in your thoughts? :)

The conclusion of the proof is that God exists, which is the very thing we aim to prove. We prove God's existence by first establishing that God's non-existence would be a sufficient condition for no intelligible experience. Accordingly, no intelligible experience becomes a necessary condition for the posited antecedent of God's non-existence. By denying the consequent of no intelligible experience, we affirm God's existence - the very thing we aim to prove.

Now why must we show that God's non-existence is a necessary condition as well as a sufficient condition for no intelligible experience (which an if-then proposition would imply)? We're not trying to prove nor establish that the absence of God is a necessary condition for no intellgible experience. Rather, what we need to establish (in order to prove God's existence) is that the absence of God is a sufficient condition for no intelligible experience. Then by denying the antecedent of no intelligible experience, we prove God's existence.

What you wrote makes sense---I am just trying to remember if I expressed Robbins' criticism correctly, because it seems like he would pick up on something like that. I remember him saying that "if" needs to be "iff" and I don't know what other part of TAG he would be referring to.

I enjoyed the discussion w/ Brian. I really liked this part: "I gave you a sound proof by your own admission. Now you want something called "a philosophical certain proof." What's that, Brian, an argument that is not sound yet appeals to autonomous reason?"

"One of the problems I have with this justification is how can an inductive argument justify the God of Christianity when it cannot justify the heart of Christianity, the Resurrection of Christ? In other words, an inductive justification for step-2 presupposes uniformity in nature, yet the existence of the Christian God requires discontinuity, the Resurrection!"

Response: What do you mean here by discontinuity? Are you saying that an inductive argument doesn't prove that the Resurrection is true? Here you mention that existence of the Christian God requires "discontinuity." What do you mean?

David Hume admitted that induction presupposes the uniformity of nature. This is essentially the problem of induction. You can only establish the uniformity of nature through induction which is self-defeating. You simply assert that God's existence solves the problem of induction because in a sense God is the most reasonable explanation ( or sufficient explanation) for why things are uniformed in nature.

In your linked post on evidentialism, you mention: "One can be justified in his belief without the truth proposition being justified."

You also mention elsewhere in that comment thread that you are surprised that philosophers don't pick up on the difference between persons being justified and propositions being justified.

You also mentioned in your back-and-forth with Kevin? when he asked when one is justified in his belief (even though having no justification for that belief) that this is rational.

(1) From this, do you mean that when one is justified in his (erroneous) belief about a wrong state capitol (from your state capitol book example), that this justification in his belief is rational?

(rationality implying the conformity of one's beliefs with one's reasons to believe, or of one's actions with one's reasons for action.)

(2) I would assume that one being justified in believing a proposition that he cannot justify is not the same thing as certainty (since we are talking about induction).

(3) Finally, I read your post from several years ago regarding Vincent Cheung. I was curious as to his thoughts regarding how we obtain knowledge. He advocates that all knowledge is revelatory and that our senses (and reasoning?) are used to simply interpret and process that information.

Any hypothetical God would need to be the creator and sustainer of all things. He would have to have created our minds and the external world and provided the fruitful connection between the two. Lastly, he would have needed to reveal these things in order for us to avoid mere conceptual necessity. We need ontological necessity or we are just pretending and hoping. If an hypothetical worldview meets these criteria it's because it is aping Christianity. In which case, the Christian God remains the solution to the one and the many.

"If an hypothetical worldview meets these criteria it's because it is aping Christianity"

As a Christian, of course I agree that the non-Christian religions are aping the one true faith; but it's still unclear to me how we can claim to deductively show that only Christianity can do the things you mentioned as being necessary for intelligible experience.

I asked you to define the non Christian God. You offered labels not definitions. Fine. I noted that if a god provided the preconditions of intelligible experience, which your two do not, then they'd be merely aping Christianity. So, are you saying TAG is invalidated by the same exact God?

Any hypothetical God would need to be the creator and sustainer of all things. He would have to have created our minds and the external world and provided the fruitful connection between the two. Lastly, he would have needed to reveal these things in order for us to avoid mere conceptual necessity.

I would say that the hypothetical god taught by the pagan philosophers of late antiquity does do all these things. I'm less familiar with Hinduism, but from what I've read, their hypothetical god, at least as understood by their philosophers, does do all these things as well.

You've confused fate and providence, but even if we import Calvinism Into the stoics at best you're aping Chistianity, in which case you would have put forth God but just under a different designation. However, you're not even doing that since these idols haven't revealed themselves let alone are they depicted as creating our minds and providing the fruitful connection between our thoughts and the mind-independent external world. If you'd take the time to think through how the pagan gods provide preconditions for intelligible experience you'd find out you come up empty. Or maybe you don't yet grasp how God alone provides these preconditions,

That is quite possible. As I mentioned, I'm new to TAG. I'm intrigued by the claims made by presuppositional apologetics, namely, being able to prove deductively not just that atheism is false, but that all non-Christian theistic systems are false as well. I'm just playing devil's advocate because it's still not clear to me how ~(Christianity is true)->(intelligibility is impossible) is valid. If I'm being too dense, perhaps you can point me to some more introductory material.

I'm not sure how familiar you are with late antique paganism, but the philosophers would claim that "the One" is the creator and sustainer of all things (including our minds and external objects), that it does provide the connection between our minds and the external world, and that it does reveal the truth through sacred texts. The Hindu philosophers would make similar claims about their false god brahma. I certainly have my reasons for not believing the claims of these pagans, but their inability to account for intelligibility has never been one of them. That's not to say that it would surprise me if these worldviews did turn out to be unable to account for intelligibility, I just don't see it yet.

Of course, as Christians we know that the "revelation" claimed by non-Christians is false, so we know that their systems fail on that count. But, if that is the strategy, then it seems like we are arguing from the position that the Bible is true, which is what we're trying to prove in the first place.

I'm also a bit confused by your comment on the Calvinistic understanding of Providence. Is that also a condition for intelligibility?

Got your latest post. What you're not grasping is all other worldviews reduce to arbitrariness and inconsistency. If one were not to, then it would be because it aped Christianity. You fail to interact with the relevance of the point. Maybe you don't grasp that a replica of Christianity doesn't refute Christianity. If you were to come across "sacred" texts, I'd suggest doing an internal critique of them.

I wouldn't say that lest we lose important distinctions. This is akin to essential and accidental properties. It is a necessary truth that all created men are mortal, so it's necessary that the created man Socrates is mortal. It's also true that his name is Socrates but it's not necessarily true in the same sense of his being mortal. It's accidentally true, for had he been named Aristotle he'd essentially be the same person. Also, we should distinguish between God's necessary and free knowledge. The latter pertains to truths he wills whereas the forner to truths that are not willed. Both are eternal and in a sense necessary but the latter class of truth could have been other had God willed, which may not be said about truths we call necessary truths.

Fallacy of composition for one thing. If all the parts of an airplane weigh less than x, must the airplane weigh less than x? Secondly, the question turns on an equivocal use of perfection as it relates to imperfection. Bottom line is, God has a morally sufficient reason for the evil he ordains.

Given your avoidance, I'm happy to leave you in your ignorance regarding the fallacy of composition as it relates to equivocation. More importantly, I commit you to your God and maker, for your problem is ultimately with Him.

1) TA's are often understood to be a priori arguments. If we see (at least) one of TAG's premises as justified by divine revelation, how does that fit into this understanding?

2) Most prominent presuppositionalists call the TAG an "indirect" argument, one that argues to its conclusion "from the impossibility of the contrary." How does an appeal to divine revelation fit into this understanding?

1. The arguments aren't apart from experience. Rather, the equipment or categories of thought all people are endowed with are apart from experience.

2. The argument is indirect because it's transcendental in nature. I have a post on this site that spells out the differences between transcendent, deductive and inductive arguments. To your second point in 2, there is no appeal to revelation in the argument as set forth.